My Nauticam NA-EM5 housing's shutter lever doesn't return to it's original position after pressed sometimes. This more frequently happens when I depress the lever partially (half way to focus). Inside the housing I've noticed the spring loaded lever that pushes on the camera's shutter button doesn't move smoothly but the external shutter lever is smooth. Anyone else have this problem? I was thinking about putting some silicon liquid on the internal lever. Any recommended silicon that's safe for housing?

I have found the same problem after a lot of use underwater despite long soaks etc.
I adjusted the screw holding the lever return bracket that sits on the left of the lever inside the housing - I did not add silicone. This helped the problem until I could get the housing serviced.

Ah, thanks for the info. After my first "fix" via jander4454's suggestion, the shutter action was again not smooth. After looking into my housing and playing with a few internal levers, I discovered that the lever with a spring that contacted my camera shutter was too snugly fit on the plastic shaft it rotated around. The lever still had a hard time rotating even after loosening screw that held the lever onto the shaft. I then just gently sanded the hole on the lever where the shaft goes in and it now rotates freely.